Coupler with unitary mounting flanges

ABSTRACT

A coupler for coupling attachments to a construction machine includes unitary mounting flanges for connecting the coupler body and the machine. The unitary mounting flange eliminates machining and/or shimming of the flanges after welding to the coupler body.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

BACKGROUND OF THE INVENTION

The present invention relates to a coupler for coupling an implement toa construction machine and, more specifically, to a coupler havingunitary mounting flanges for securing the coupler to the constructionmachine.

It is common to have more than one bucket for an excavator or backhoe.For example, a wide, large capacity bucket with a straight cutting edgeis commonly used for cleanup and leveling or where the material to beexcavated is relatively soft while a general purpose bucket which istypically smaller, stronger and has hardened teeth and/or side cuttersis often used to break through hard soil or rocks. Buckets also come ina number of sizes and shapes for particular applications. In addition,the capabilities of excavators and backhoes have been expanded farbeyond excavation with attachments for boring, ripping, crushing,compacting, cutting and lifting. Many excavators and backhoes include acoupler or hitch, such as the quick coupler disclosed in U.S. Pat. No.7,828,070, to speed and simplify the engagement and disengagement ofbuckets and other attachments. While the weight of the coupler mayreduce the capacity of the machine, a coupler can substantially increasethe efficiency and flexibility of the machine by enabling rapid changesof buckets and other attachments.

A coupler typically comprises a coupler body including elongate spacedside plates to which are attached respective flange plates which includeportions projecting above the coupler body to define the interface withthe machine. The machine's stick is positioned between the projectingportions of the flange plates and the coupler is pivotally secured tothe stick by a pin secured in aligned apertures in the stick and theflange plates. The coupler is also typically attached to the machine bya second pin which is secured in a spaced apart second pair of aperturesin the flange plates and a cooperating aperture in a control link.Extension or retraction of a hydraulic bucket or attachment cylindermoves the control link pivoting the coupler relative to the stick.

The elongate body of the coupler typically includes a hook portion atone end which is engageable with a “front pin” affixed to the bucket orother attachment that is to be coupled to the machine. A slot-likemounting portion proximate the second end of the body is arrangedapproximately normal to the hook portion and is engageable with a “rearpin” on the attachment. After the front pin is seated in the hookportion, the coupler is pivoted relative to the stick by extension ofthe hydraulic attachment cylinder to engage the rear pin in the mountingportion of the coupler's body. To prevent the front and rear pins fromdisengaging from the respective hook and mounting portions of thecoupler's body the coupler is typically locked to the attachment by oneor more latches which are commonly hydraulically operable in a quickcoupler.

The width of the stick and the control link and the distance between themounting pin plates on buckets or other attachments varies for machinesand attachments from different manufacturers and for different models ofmachines and attachments from the same manufacturer requiring spacingthe inner surfaces of the flange plates various distances and offsettingthe flange plates from the coupler body's side plates. The flange platesare typically offset from the side plates by inserting a spacer platebetween the side plate and the flange plate. The spacer is welded to theflange plate and to the side plate of the coupler's body but the weldingon the inside surface of the flange plate at the base of the projectingportion commonly distorts the unrestrained projecting portion of theflange plate. Typically, it is necessary to machine and/or attachspacers or shims of varying thickness to the inner surfaces of theflange plates after the welded coupler frame has cooled for severalhours to obtain the proper fit up to the machine's stick. What isdesired, therefore, is an improved coupler which is lighter, reducespart count and does not require machining or shimming of the innersurfaces of the mounting flanges after welding to the coupler body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective illustration of a quick coupler for coupling anattachment with a construction machine.

FIG. 2 is a perspective view of a coupler frame comprising unitarymounting flanges.

FIG. 3 is an elevation view of the outer surfaces of an exemplaryunitary mounting flange.

FIG. 4 is an elevation view of an end of the exemplary unitary mountingflange of FIG. 3.

FIG. 5 is a bottom plan view of the exemplary unitary mounting flange ofFIG. 3.

FIG. 6 is an elevation view of the inner surfaces of the exemplaryunitary mounting flange of FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring in detail to the drawings where similar parts are identifiedby like reference numerals, and, more particularly to FIG. 1, a coupler20 for a construction machine, such as a back hoe or an excavator,enables rapid coupling and uncoupling of the stick 22 of the machine andattachments 24, such as buckets, jack hammers and compactors. A coupler20 comprises, generally, a coupler body 26 affixed to a pair oflaterally spaced mounting flanges 28, 30 which include portionsextending above the coupler body and defining mounting pin apertures.The inner surfaces of the spaced projecting portions of the mountingflanges 28, 30 are arranged to interface with respective sides of thestick and the control link. The coupler is secured to the machine by astick mounting pin 32 and a control link mounting pin 34 which aresecured in apertures in the stick 26 and control link 36 and respectivepairs of apertures defined by the projecting portions of the spacedmounting flanges.

Referring also to FIG. 2, the frame 70 of a coupler comprises,generally, a body frame 72 and a pair of flanges including portionsprojecting upward from the body frame. The body frame 72 of the couplercomprises, generally, a pair of elongate side plates 74, 76 which arespaced apart by a front plate 78 affixed transverse to the side platesproximate the first (front) ends of the side plates and a rear plate 80affixed transverse to the side plates proximate the second (rear) endsof the side plates. A slot-like hook portion 82 is defined by the sideplates proximate their first ends and extends generally longitudinallyin the side plates. The side plates 74, 76 also define a slot-likemounting portion 84 proximate the second ends of the side plates whichextends into the side plates in a direction substantially normal to thelongitudinal axis of the hook portion.

To secure the coupler 20 to the stick 22 of the construction machine,the operator moves the stick to locate it between the inner surfaces ofthe projecting portions of the flanges 28, 30 and align an aperture inthe stick with apertures defined by the flanges. The stick mounting pin32 is inserted in the cooperating apertures in the stick and the flangesand secured, for example, by a collar 33 affixed to each end of thestick mounting pin. The operator then rotates the control link 36 byactivating a hydraulic attachment or bucket cylinder (not shown)attached to the control link to align an aperture in the control linkwith a second pair of holes defined in the flanges. The coupler ispivotally secured to the machine's stick by the stick mounting pin and acontrol link mounting pin 34 which may be in secured cooperatingapertures in the control link and the flanges of the coupler by collars33.

To secure an attachment 24, such as a bucket, to the machine theoperator of the maneuvers the stick 22 to locate the side plates 76, 78of the coupler body 26 between spaced mounting plates 38, 40 on theattachment and retracts the hydraulic attachment cylinder attached tothe control link 36 to rotate the coupler about the stick mounting pin32 enabling a front pin 42 affixed to the attachment to enter the hookportion 82 of the coupler body 26. A spring biased locking knuckle 44,depressed by entry of the front pin into the hook portion, extends tolock the front pin into the hook portion. The operator then extends theattachment cylinder rotating the coupler 20 about the front pin 42causing a rear pin 46 of the attachment to enter the mounting portion 84in the coupler body. Extension of a hydraulic locking cylinder (notshown) located within the coupler body extends a locking wedge 48 intothe mounting portion 84 securing the attachment to the stick 22 of theconstruction machine by locking the rear pin 46 in the mounting portionand the front pin in the hook portion. Hydraulically withdrawing thelocking wedge 48 and the locking knuckle 44 enables separation of thecoupler and the attachment.

The distance between the outer surfaces of the coupler body's sideplates 74, 76 is dictated by the separation of the inner surfaces of theattachment's mounting plates 38, 40, which may be defined by bosses 50and the distance between the innermost surfaces of the projectingportions of coupler's flanges 28, 30 is dictated by the outer width ofthe machine's stick 22 and control link 36. A spacer is typicallyinserted between each coupler side plate and flange plate to offset thesurfaces to provide close fitting but freely movable interfaces betweenthe coupler and the machine's stick and between the coupler and theattachment. However, heating and cooling accompanying welding on theflange plate's inner surface at the base of the projecting portioncommonly distorts the projecting portions of the flange plates. It isoften necessary to machine and/or add spacers to the inside surfaces ofthe projecting portions of the flange plates after the welded couplerhas cooled for several hours to obtain the correct separation andorientation of the surfaces of the flange plates that interface with themachine's stick. The inventor reasoned that a unitary mounting flangeincorporating the offset interfaces to both the coupler frame and themachine in a unitary element would eliminate the need for a spacerbetween the coupler body and the flange reducing the part count,enabling thickening and stiffening of the portion of the mounting flangewelded to the coupler body and separate the flange to coupler bodywelding from the projecting portions of the flange minimizing weldinginduced distortion of the flange and the need to machine and/or shim theinner surfaces of the flange to obtain the proper fit up to themachine's stick and control link. In addition, the inventor reasonedthat casting or forging the unitary flange would enable optimizing theplacement of material making up the flange reducing the weight of thecoupler.

Referring also to FIGS. 3-6, a coupler frame 70 includes a coupler bodyframe 72 having spaced elongate side plates 74, 76 to which are affixedrespective unitary mounting flanges 86, 88. An exemplary cast or forgedunitary mounting flange 88 (unitary mounting flange 86 is preferably amirror image of mounting flange 88) comprises, generally, a machineinterface portion 90, a coupler interface portion 92 and a web portion94 uniting the coupler interface portion and the machine interfaceportion. The web portion 94 of the unitary mounting flange comprisesgenerally a web 96 defined by a first (inner) surface 98 and a spaced,opposing second (outer) surface 100. One or more bosses 134, 136providing bearing surfaces for collars 33 which are commonly used tosecure the stick mounting pin 32 and the control link mounting pin 34may project from the second surface 100 of the web. Preferably, theunitary mounting flange is cast or forged.

The coupler interface portion 92 which may include portions locatedproximate a first edge 102 of the web portion 94 projects outward fromthe first surface 98 of the web 96 to a substantially planar couplerinterface surface 104 which is arranged for abutment with a respectiveside plate 76 of the coupler body's frame 72. The coupler interfacesurface 104 is preferably defined, in part, by the perimeter edge 106 ofthe coupler interface portion 92 which may include portions extendingalong the first edge 102 and preferably includes portions distal of thefirst edge and arranged to be substantially coextensive with the uppersurface of the coupler side plate, for example the upper surface 77 ofthe coupler side plate 76, when the coupler interface surface is inabutment with the side plate. The coupler interface surface is alsopreferably defined by inner edges 108 and 110 spaced apart from andextending substantially parallel to portions of the perimeter edge. Theinner edge 108 preferably defines a first relief surface 112 and theinner edge 110 preferably defines a second relief surface 114. Therelief surfaces 112 and 114 are preferably spaced from the secondsurface 100 of the web 96 a lesser distance than the coupler interfacesurface 104 substantially reducing the weight of the unitary mountingflange and thereby the weight of the coupler.

The web 96 unifies the coupler interface portion 92 and the machineinterface portion 90 of the unitary mounting flange 88. The machineinterface portion 92 may comprise plural spaced machine interfaceportions 120, 122 projecting outward from the first surface 98 of theweb 96.

Raw surfaces of the coupler interface portion 92 and the machineinterface portion 94 most remote of the first surface 98 of the webportion 94 are preferably machined to provide a planar coupler interfacesurface 104 offset 132 from parallel machine interface surface(s) 124,126. The machine interface surfaces 124, 126 may coplanar or may beoffset from each other if required to match the respective widths of thestick and control link of a particular machine.

Plural apertures 128, 130 arranged to cooperate with respectiveapertures in the control link and the stick and receive the stickmounting pin and the control link mounting pin are defined by portionsof the machine interface portion 90 and the web portion 94 of theunitary mounting flanges 86, 88.

The unitary mounting flanges 86, 88 are preferably attached to thecoupler body by abutting the coupler interface surface 104 with therespective side plate, for example side plate 72, 76 of the couplerbody's frame 72 and welding along portions of the perimeter edge 106where the coupler interface surface and the side plate abut. The offsetcoupler interface surface 104 and machine interface surface(s) 124, 126of the unitary mounting flange eliminates the need for a spacer betweenthe coupler body side plates and the mounting flange reducing the partcount and eliminating welding on the surface of the projecting portionof the flange. In addition, the portion of the unitary mounting flangewelded to the coupler body is thicker and stiffer than the priormounting plate which combined with distancing the mountingflange-to-coupler body welding from the projecting portion of themounting flange reduces distortion of the portion of the flangeinterfacing with the machine eliminating the need to machine and/or shimthe inner surface of the projecting portion of the flange.

The unitary mounting flange reduces the inventory required to producecouplers for machines with a range of stick and control link widths andarrangements, eliminates machining and shimming of the flanges afterwelding and reduces the weight of the coupler.

The detailed description, above, sets forth numerous specific details toprovide a thorough understanding of the present invention. However,those skilled in the art will appreciate that the present invention maybe practiced without these specific details. In other instances, wellknown methods, procedures, components, and circuitry have not beendescribed in detail to avoid obscuring the present invention.

All the references cited herein are incorporated by reference.

The terms and expressions that have been employed in the foregoingspecification are used as terms of description and not of limitation,and there is no intention, in the use of such terms and expressions, ofexcluding equivalents of the features shown and described or portionsthereof, it being recognized that the scope of the invention is definedand limited only by the claims that follow.

I (We) claim:
 1. A unitary mounting flange for connecting a coupler bodyto a machine, said mounting flange comprising: (a) a coupler interfaceportion including a coupler interface surface spaced apart from anopposing first surface; and (b) a machine interface portion united withsaid coupler interface portion and including a machine interface surfacespaced apart from said first surface a lesser distance than said couplerinterface surface.
 2. The unitary mounting flange of claim 1 whereinsaid coupler interface surface and said machine interface surface aresubstantially planar and said machine interface surface is substantiallyparallel to said coupler interface surface.
 3. The unitary mountingflange of claim 1 further comprising a second machine interface surfacesubstantially parallel to said first machine interface surface.
 4. Theunitary mounting flange of claim 3 wherein said second machine interfacesurface is substantially co-planar with said first machine interfacesurface.
 5. The unitary mounting flange of claim 1 further comprising athird portion united with said coupler interface portion and saidmachine interface portion and having a second surface spaced apart fromsaid first surface a lesser distance than said coupler interfacesurface.
 6. The unitary mounting flange of claim 1 further comprising athird portion united with said coupler interface portion and saidmachine interface portion and having a second surface spaced apart fromsaid first surface a lesser distance than said machine interfacesurface.
 7. The unitary mounting flange of claim 1 further comprising asecond machine interface surface substantially parallel to said machineinterface surface.
 8. The unitary mounting flange of claim 1 whereinsaid coupler interface surface is further defined by a perimeter edge ofsaid coupler interface portion and a second edge spaced apart from saidperimeter edge and extending substantially parallel to a portion of saidperimeter edge, said second edge defining a relief surface spaced apartfrom said first surface a lesser distance than said coupler interfacesurface.
 9. The unitary mounting flange of claim 1 further comprising acast web portion uniting a cast coupler interface portion and a castmachine interface portion.
 10. The unitary mounting flange of claim 1further comprising a forged web portion uniting a forged couplerinterface portion and a forged machine interface portion.
 11. A couplerfor securing an attachment to a machine, said coupler comprising: (a) acoupler body; and (b) a unitary mounting flange comprising: (i) acoupler interface portion including a coupler interface surface spacedapart from an opposing first surface, said unitary, mounting flangeaffixed to said coupler body with said coupler interface surfaceabutting said coupler body; and (ii) a machine interface portion unitedwith said coupler interface portion and including a machine interfacesurface spaced apart from said first surface a lesser distance than saidcoupler interface surface, said machine interface portion defining anaperture to receive a pin for securing said coupler to said machine. 12.The coupler of 11 further comprising a web portion of said unitarymounting flange, said web portion uniting said coupler interface portionof said unitary mounting flange with said machine interface portion ofsaid unitary mounting flange.
 13. The coupler of claim 12 wherein saidweb portion, said coupler interface portion and said machine interfaceportion are cast.
 14. The coupler of claim 12 wherein said machineinterface surfaces comprises: (a) a stick interface surface; and (b) aspaced apart control link interface surface.
 15. The coupler of claim 14wherein said stick interface surface is co-planar with said control linkinterface surface.